Stop a Train with a Pebble?

Question

Some one said to me once that if you throw a pebble at a high speed train you could stop it if you threw it hard enough and in the right place - is this as stupid as it sounds!?

Answer 1

Totally stupid,And dangerous.

Answer 2

Actually, it is more stupid than it sounds.

Answer 3

youve been bull shitted!!

Answer 4

yes so stupid and it    KILLS KILLS KILLS KILLS GET IT

Answer 5

I`ll have to try it and see.

Answer 6

No, because the speed of the pebble + the speed of the train = impact speed. However you then have the problem of the mass of the two objects as well.

Answer 7

You could kill the driver doing this.

It would be murder.

Don't be so silly.

Answer 8

Only if the stone was big enough and you hit one of the break pipe couplings or the valve lever,,,,,,or killed the driver,,the break pipes (2 of them) are slung at each end of coaches and waggons,,,they join by a small lever clip the valve tap sits just where they  go into the undercarriage of the waggon,,,,

Answer 9

There have been several instances of death and injury being caused by bricks and other objects being dropped from bridges on to trains. Don't be so stupid as to try anything that involves throwing a missile, however small, at moving transport.

Answer 10

If you threw the pebble through the windscreen and it killed the driver, that would stop the train.

The drivers of trains have to acknowledge an alarm every so often, if this alarm is not answered the train will stop.

I don't advise you try my theory out on a real HST though.

Answer 11

You'll probably die becos if it worked the train would go i to you.

I doubt it would work and why would you want to do that anyway!?

Answer 12

Yep, pretty much.  Think of it this way, you'd be hard pressed to stop a train with a high powered rifle which is throwing a piece of lead at a heck of a lot faster speed than any pitcher ever born.  It's not gonna stop a train.

Answer 13

No even if it got hung up some where important it would turn to dust,wouldn't phase it,keep this in mind,if you hang around tracks you can be charged with a felony,if cought of course.

Answer 14

sounds stupid.. i wouldnt risk de-railing a train by throwing a pebble at the trax

Answer 15

I dont think so, but every time I say no way I am way wrong, seems to be exceptions to everything.

I guess a "right place" might be between the eyes of the eingineer, in theory of course.

I have heard old timers say a handful of nickels, wedged tightly beneath each wheel of a steam engine they could not move, no matter the size.

But if that engine could move even one inch that was all it needed to get rolling. Supposedly it was demonstrated numerous times.

Answer 16

The person who said this I bet was a Physics Graduate - its a common trick question in Physics finals!!

Well, yes it is true, you can also stop a train with a grain of rice.

Let me explain - you need to think clearly and logically and have a basic understanding of the fundamental laws of energy and motion.

You have a 500 ton train racing along at say 70 miles per hour. You stand on the tracks and throw a pebble at it head on - what happens?

Well, the train is way more heavy than the pebble so its obvious that the train is going to hit the pebble and the pebble will be pushed in the oppersite direction by the train.

This is the key phrase - PUSHED IN THE OPPERSITE DIRECTION.

The pebble was traveling in one linier direction, then the train has pushed it in the complete oppersite direction. The most elementary laws of physics (and common sense) states that if a body is traveling in one direction, irrespective of mass or velocity, if it has to change direction it has to stop first.

Therefore, at the very instant in time, which in this case is immeasurable, that that pebble touches the train, before the train can push it in the oppersite direction it MUST stop, therefore, at that moment in time the pebble and the train are stationary.

Its a really weird concept which needs a clear head to understand, but is is true!!

If you want the maths surrounding this, contact me and I will email you an attachment.

Answer 17

This sounds like a trick answer.

i.e.       if it went through the drivers open window, knocked him/her out, causing the dead-mans handle to be released.